Java tutorial
//package com.java2s; import java.text.DecimalFormat; public class Main { public static String FormetFileSize(long fileS) { DecimalFormat df = new DecimalFormat("#.00"); String fileSizeString = ""; if (fileS < 1024) { fileSizeString = df.format((double) fileS) + "B"; } else if (fileS < 1048576) { fileSizeString = df.format((double) fileS / 1024) + "K"; } else if (fileS < 1073741824) { fileSizeString = df.format((double) fileS / 1048576) + "M"; } else { fileSizeString = df.format((double) fileS / 1073741824) + "G"; } return fileSizeString; } }